| Project Detail |
How we and other animals ‘make up our minds’ is an everlasting question that has occupied philosophers and scientists for centuries. Sensory-evoked activity patterns, memory engrams and internally generated brain activity conveying the animal’s internal state are meant to integrate to promote an appropriate behaviour. Still, direct evidence for how integration works on the network, the neurophysiological and the molecular level remains limited. Exemplifying internal needs with tiredness and hunger, and focusing on the numerically simple brain of Drosophila, we here test a parallel filter hypothesis to explain how sensory and internal states are integrated across the relevant centres of the fly brain. We posit that parallel neural filters will have changed permeability for sensory stimuli and to compete: e.g. if hungry, neural networks promoting food approach behaviour will change their permeability for sensory cues relative to those promoting sleep. Our approach will visualise neural activity, while recording online fly behaviour related to hunger, sleep and experience on a treadmill. It will tackle the physiological basis shaping filters, including oscillatory cell and network activities as well as synaptic gating, while recording whole brain activity. We capitalise on our expertise in functional imaging and previous discoveries of hunger and sleep gates as well as their synaptic and network substrates. We will investigate and interfere with key molecular factors underlying filtering to directly challenge network integration and behavioural outcome. Finally, we will remote control competing parallel filters, to test whether sensory permeability can switch the animal’s state between an ego- and an allocentric-like world view and whether depression-like states related to learnt helplessness will favour an egocentric filter setting. Understanding neural filter properties should allow further insights to the physiological basis of depressed states. |
